Grounding an Antenna Mast

Last year I put up a TV antenna mast. I didn't want to screw it to the
roof, so I ran three 10 foot lengths of 1 1/4 EMT conduit up the side of
the house, and bracketed it to the side of the house. I buried the
bottom about 10 inches in the soil. That got the top of that mast about
8 foot above the roof. Which is where the antenna sits. (I had a machine
shop make me some sturdy splicers to connect the EMT conduit sections
together, because those connectors sold for EMT are too weak for my
use). There are also a few guy wires to secure this mase in case of
wind. Those are connected to the side of the house.
Anyhow, I never really grounded this mast, and think I should. That 10"
buried into the soil is not really a suitable ground. One of the ground
rods for my house's electrical system is only about 8 feet from the
mast, so I can run a wire to that. My problem is how to connect that
wire to the conduit. The commercial ground rod clamps are not big enough
to go around that conduit. I thought about clamping it with a stainless
steel hose clamp, but that's not the best connection. A muffler clamp os
my other thought, but the way they rust, I'd almost think a S.S. hose
clamp would be the better if the two. I suppose I could also drill a
hole in the conduit and put a bolt thru is, but I'd prefer to not weaken
the conduit with a hole.
Maybe some of you will have a better idea about what to use to clamp it.
I'll probably use #8 or #10 bare copper wire for this, or insulated,
depending on what I have laying around.
Ideally, I think a Stainless Steel muffler type clamp would be best, if
I could find such a thing.

That's good to know, but DD, why would these be better than stainless
steel hose clamps? I assume you mean -- or at least I mean -- the
kind with a worm gear. One of them would make more contact with the
conduit than one of these muffler clamps would.

I doubt that boring a hole through the EMT to connect the ground is
going to be a problem. Think it out: You're at the bottom of the mast,
you've bracketed and guyed the mast along the entire run, what forces
other than gravity/weight of the mast are likely to be applied to the
area where you will drill?
Your more immediate problem is likely to be rust at the base. Did you
leave the end open and sitting on a bed of gravel? Where is the water,
condensate that will build up and pool at the bottom of the mast going
to go?
I had a freestanding, 40' Rohn tower for my TV antenna and rotor. The
base section was set in 24" x 24" x 48" poured concrete foundation with
3/4" steel rebar driven outward of the hole before the concrete was
poured. Note that the Rohn tower is heavily galvanized and the base
section, IIRC was 36" - 42" in length. It took about 35 years but
eventually it rusted out at the base (where the first section connects
to the base piece and I came home one day to find it laying across the
driveway. I didn't leave a drain for the base.
Fortunately there was no damage other than to the antenna which had seen
better days anyway. As luck would have it, I found that regular
galvanized pipe made a very nice reinforcing insert when slipped down
inside the tower pieces. The galvanized pipe was placed and extended
about 18" above the base. That setup and a friend with an aerial bucket
and I was back in business. If anything, the tower is more secure than
before. Yeah, I didn't do anything about the drainage issue; it will
rust out again but not in my lifetime and I added a heavy steel standoff
bracket (mfg by Rohn) which is attached to the studs in the sidewall of
my house.

I think you are.
This was a "belts and suspenders" move on my part. The concrete alone
was sufficient and there's been no evidences whatsoever of deterioration
there. Think of the 14x24x48 poured base with LEGS. I think I also
pounded in a couple of metal fence T-posts as well. Even with some
fairly stiff wind storms here, even without the relatively new bracket
to the house (remember, that tower was unguyed and unbracketed until the
rust out) that sucker was and remains perfectly plumb.

In my installation, I drove an 8' or 10' ground rod adjacent to the
tower base and then used a pre-terminated length of automotive battery
cable between the ground rod and the tower, fastening the cable to the
tower through one of the leg's two bolts.

I was thinking about that. I think I'll use a S.S. U-bolt and clamp half
of a standard two piece brass ground rod clamp, and clamp that piece to
the mast. Those have a screw on them. Brass is probably better than
copper against steel. (Like brass valves in galvanized pipe)
I'm glad someone mentioned a weep hole for water. I suppose some water
can still get in the pipe at the pieces that connect the pipe sections,
even though I covered the top of the pipe with duct tape before I raised
it. Maybe I should drill at least a 1/8" hole right at ground level,
even if the water can soak into the soil.

I'm not sure what those look like, but if I can find one that will fit a
1 1/4 inch pipe, that seems like it would be ideal.
The local hardware store dont have them, but maybe one of the big box
stores does. But I dont live near any of them. About once a month I will
make the 1.5 hour drive (each way).

Oh, never mind. He left a URL in his post. I just looked at it and that
looks perfect. I wonder if Home Depot ships stuff like this? ( I dont
think so). There is no H.D. within a reasonable driving distance.
Menards is closest and that's 1.5 hours away. That's the drawback of
living in a rural area.

The large cables used for grounding may be aluminum. Steel and aluminum
may not go together well. Copper is expensive but may be a better choice.
Don't forget a lightening arrestor for the antenna cable
Dave M.

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